Field of the Invention
This present disclosure generally relates to underwater lighting systems, and more particularly for lighting systems for use in swimming pools, spas and the like, which provide an indication to a user indicating that at least one of the lights in a lighting system may need to be replaced.
Background of the Invention
In-ground swimming pools and spas are often installed with lights, typically in a horizontal row a short distance below the waterline. The underwater lighting has a pleasing visual effect and permits safe swimming during nighttime.
Commercial pools in most jurisdictions throughout the country and residential pools in some cities or counties have minimum illumination requirements, typically set and enforced by health departments and local building codes, to provide for safe pool use.
Assuming that a specified pool light delivers predictable illumination, in lumen output, pools are designed with the number of lights and niches required to deliver at or above the required illumination, in lumens, for the square footage of the pool surface area. Pools historically have been illuminated with submersible incandescent lights which deliver relatively constant lumen output throughout the life of the incandescent bulb. A typical incandescent bulb has some lumen depreciation in its first 100 hours of use and then maintains a steady state lumen output until the end of its life. Thus, as long as the incandescent bulb is emitting light, the incandescent bulb is emitting the prescribed amount of light.
In contrast, the lumens emitted by LEDs and submersible LED light fixtures depreciate appreciably and predictably over the life of the LEDs. This gradual depreciation over the life of an LED, however, gives no indication as to when the LED will stop delivering a minimum prescribed lumen output for safe illumination of a pool. It is desirable therefore to provide an indication that an LED output has depreciated below a minimum lumen output level.